Seal off boot area taje grommets out if wheel well

Nice one mate, thanks

They have 2 little holes in the top of the battery on the sides, they usually have a little red or black plastic pipe coming out of them which you just need to attach some vacuum hose or similar to, then lead this out the car somewhere, mine goes through the wiring grommet for the number plate light. It's right in the middle of the boot at the back

Best way to vent the battery?

You will need to vent the gas off the battery when it charges or you risk an explosion. A car battery gives of hydrogen as it charges and 4% concentration will turn your car into a bomb.

I've got mine relocated with an isolation switch, I've run the positive with an inline fuse straight to the isolation switch then the other terminal on the switch goes into the engine bay into a distribution block. The negative terminal I've earthed straight to the chassis in the boot with a nice thick cable. I've also run a separate fused permanent live for the ecu and Central locking unit. And I've used the original battery tray and bolted it to the floor in the boot If that makes sense lol it's just how I've done it but it works and is pretty straight forward

I'm wanting to move my battery into the boot of my corsa b, I have a positive cable from a BMW, I know I need battery box, negative cable, I also want to use a isolator switch, anyone give me any advice on how to do this?

Thanks